According the United Nations Food and Agricultural Organization (UN FAO), the world's population will exceed 9.6 billion people by the year 2050, which will require significant improvements in agricultural to meet growing food demands. There is a need for improved agricultural plants that will enable the nearly doubled food production demands with fewer resources and more environmentally sustainable inputs, for plants with improved responses to various biotic and abiotic stresses, as well as improved nutritional composition.
Today, crop performance is optimized primarily via technologies directed towards the interplay between crop genotype (e.g., plant breeding, genetically-modified (GM) crops) and its surrounding environment (e.g., fertilizer, synthetic herbicides, pesticides). While these paradigms have assisted in doubling global food production in the past fifty years, yield growth rates have stalled in many major crops and shifts in the climate have been linked to production instability and declines in important crops, driving an urgent need for novel solutions to crop yield improvement. In addition to their long development and regulatory timelines, public fears of GM-crops and synthetic chemicals have challenged their use in many key crops and countries, resulting in a lack of acceptance for many GM traits and the exclusion of GM crops and many synthetic chemistries from some global markets. Thus, there is a significant need for innovative, effective, environmentally-sustainable, and publicly-acceptable approaches to improving the characteristics of crop plants.
Like humans, who utilize a complement of beneficial microbial symbionts, plants have been purported to derive a benefit from the vast array of bacteria and fungi that live both within and around their tissues in order to support the plant's health and growth. Endophytes are symbiotic organisms (typically bacteria or fungi) that live within plants, and inhabit various plant tissues, often colonizing the intercellular spaces of host leaves, stems, flowers, fruits, seeds, or roots. To date, only a small number of symbiotic endophyte-host relationships have been analyzed in limited studies to provide fitness benefits to model host plants within controlled laboratory settings.
Efforts to modulate compositions, such as fats or proteins, in seeds of crop plants have been largely unsuccessful, as changes in one specific component are often at the expense of another, or at the expense of total plant yield. Thus, there remains an outstanding need for compositions and methods that can modulate levels of individual seed nutrients (e.g., protein, fat, carbohydrate, fiber, moisture, ash, or Calories) without negatively impacting yield (i.e., no statistical negative impact to yield).
There remains a great need to develop better plant-endophyte systems to confer benefits to a variety of agriculturally-important plants, for example to provide improved nutritional quality traits in the seeds produced from such plants. Provided herein are methods of improving the nutritional profile of seeds grown from plants heterologously disposed to endophytes.